Shaped charge assembly and gun



Aug- 2, 1960 H. H. MoHAuPT 2,947,250 y SHAPED CHARGE ASSEMBLY AND GUN 2 Sheets-Sheet 1 Filed Sept. 24, 1951 TF JQ.E

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SHAPED CHARGE ASSEMBLY AND GUN Filed sept. 24, 1951' Aug. 2, 1960 2 Sheets-Sheet 2 ff ld-A /77' TaR/Vf ys 2,947,250 v SHAPED CIGE ASSEMBLY AND GUN Henry H. Moliaupt, Swarnpscott, Mass., assignor, by mesne assignments, to Welex, Inc., Fort Worth, Tex., a corporation of Delaware Filed Sept. 24, 1951, Ser. No. 247,984

2 Claims. (Cl. 102-20) This invention relates to improvements in means' for perforating casing in wells and for perforating and fracturing earth formations around well bores.

In the perforating of oil wells by the use of' shaped charges, i.e., explosive charges provided with surface cavities lined with an inert material such as metal, it has been the general practice to lower into the well acarrier' type perforating, and it has been' by reason'of the in.-A creased eiciency and more eective resultsV of shaped charge perforating that such new method has been able to' replace to a large extent the older method. Obviously, any means for decreasing the cost and expense of' shaped charge perforating wouldV be of advantagev to the.

tes Patent() 2,947,250 fPjtented Aug. 2,1960

of initial detonation.v Heretofore it has been the prac' tice to use booster charges of lesser density, which booster-charges are set olf by the initial ring means and which in turn set off the higher density mainkcharge. It is an object of this invention tor provide means within the charge itself for doing away with the necessity of such a booster charge whereby again to decrease the cost of this type perforator.

Again an expense attendant upon shaped charge per` forating lies in gun life problems. Upon use and reuse: of a particular gun eventually such gun will outlive its: usefulness. One of the principal causes of this is damage`4 occasioned to the ports through which thev charges must re, .such damage being occasioned yby the" force of the`- explosive against the port. It is an object of this inven-A tion to devise a charge assembly whereby such charge: assembly inherently affords protection for the gun ports'. thereby preserving the longevity of the gun.

Further objects of the invention Vwill appear herein after.Y

In the drawings:

Figure l shows a side elevtaional view of a gun bodyincorporating the novel assembly placed within a well;`

Figure 2 shows a' vertical section view taken on thee line 2--2 of'Figure l;

Figure 3 shows in part a similar view to Figure 2,V bu't; demonstrates: a modification of the invention;v and Figure 4 shows ak View similar to Figure' demonstrating the same embodiment of Figure 3 in' conjunctionwith a dierent type gun port sealing plug than is shownA newer method in competing with the older and' would.r

constitute a considerable contribution to the oil industry.

It is with such a means. that the instant invention isV concerned.

One of the difficulties attendant upon prior shapedA charge perforating has been occasioned in the assembly ofv the charges within the gun prior to runningthe gun into` the well. Thus, in standard practice, a numberA of' siveE itl has been diicult to insert the. various.Y charges within. the gun and at the same time ei`n`ciently providev the firing means, usually a detonating fuse, sucl asPlif macord, adjacent the rearward end of each. charge. Sim

ilarly, effective means for placing andsecuringthe chargesr4 in` their proper positions within the gun body havefbeen,

diicult of achievement.

Consequently, an object ofthe instant.inventionisto.

provide a novel charge assembly adapted forcombination with the gun in such a way as to provide an easy.

positioning of the detonating fuse in its proper proximity to the charges upon their positioning withinv they gun.

Similarly, it is an object of this invention to provide the charge assemblies themselvesY adaptedl for cooperativepositioning within the gun in such. mannerA as to make easier such positioning. ln this there is provided a,y double ended charge assembly whereby the centerof thecharge is substantially lled with. explosiveiand4 two cavitied; ends provided, the charge thus firing in: two directions. Double ended charges of this type are not new in the art, butthis particular charge assembly and its. adaptability to easy positioning within the gun body is believed to be novel.

Another expense attendant upon this type perforator lies in the nature of the charges themselves, sucl'i charges iinv essence, the invention of this application' ctinsistsinl the concept of providing' a full ,enclosure within Ythe charge assemblyV through which the ydetonating fuse may-'jv bestrungY so that the` force 'of such detonating-fuse avail able to detonate the charge will be enhanced and thus a booster madeV unnecessary. the concept ofV providing bores inthe. charge assemblies.,

such:boresbeingalignedupon positioning'of the chargesz within the guns,` sothatthe Primacord` may Ybe easily;

efficiently and rapidly threaded through the said bores.A A specicf'eature of the invention lies in the provision of: a'v rigidhousing for thecharge assembly whereby the housing'is'of such a length as to extend ateither end into` the' gun ports so` that the charge may be inserted into the gun"A ports and retained in its proper position therein'. Additionally, such extended housingA provides a protection for the gun port against y the force ofthe exploding, charge.

Referring to the drawings" andV particularly -tovliigures-r l and 2a'gunbody 1) preferably cylindricaliis. shown havinga round closure 1'2on its lower end7 and afrusto-, conical cap,V 14 at tsupper end.y Theupper. capA enclosesl a detonatingmechanism for the shapedcharge assembly lgandthe gun islowered: into thewell` ZiSgbyl a conductorcable 20, whiehconnectstoihe detonatingmeehan-ismr whicliin. turn=res al detonating fuse; ZZfwhich-.sets oit the sliapedfchargeassemblies.16. The shaped-chargeasf semblies 'e jets, through the gun ports, v such as 24,j 26

medial-member is `providedwith a: transverse passageway? BStoreceivefthe. detonating fuse 2,2: andwithfanLinterf secting; axial bore Ail communicatingz the Ad'etonating'fse withtWo main. explosive charges. 42'.v In .theabsencerof'l booster. charges, thefexplosive chargesV 42.` {ill-their'I spectivel explosive v chambersV and also" the' axialbore 40 The explosive charges 42 are cavitied and provided with It likewise consists' in`- liners 44 which are in retracted disposition with respect to the extremities of the housing 34 and which are directed outwardly through the gun ports 24 and 26.

' The gun ports 24 andV 26 are shown having interiorly threaded inner portions 46 and counterbored portions 48 of increased diameter. A threaded sealing plug 50 is shown for the gun port 24, having a flange 52 adapted to seat against the shoulder 54 of the gun body 10, there being a sealing ring interposed between said iiange andl said shoulder. Such sealing plug does not extend entirely through the gun port 24 and the said gun port 24 pro'vides a retaining -seat for the extremity of the housing 34. The sealing plug is dished as at 56 whereby but a thin metal wall provides the only obstruction for the passage of the jet through the said plug and through the well casing.

Instead of the sealing plug 50, there is shown for the port 26 a sealing disk 58, which sealing disk may be hammered into the counterbore 48 of the gun port 26 in tight t atop the sealing ring 60. It will be understood that while two diierent sealing means are shown in this embodiment of the invention, such sealing means are not a part of the invention but are merely exemplied for brevity and to show the adaptability of the invention to a variety of such sealing plugs.

By the aforedescribed invention it may easily be seen that elective reduction in the cost of the shaped charge perforating method, both in the matter of material cost and in the matter of operational cost, is effected. The provision of the coniining medial portion 36 enables the full explosive force of that po-rtion of the detonating fuse within the charge assembly to be directed into the respective main explosive charges, thus avoiding the necessity of booster charges. The provision of a transverse passage in each charge assembly for receiving the detonating fuse and the aligned position of the passageways of the various charges upon assembly of the gun permits a simple threading of the detonating fuses through the charge assemblies after insertion of said assemblies within the gun. First, the charge assemblies are merely inserted through the gun ports, the sealing plugs or disks beingremoved. Next, the sealing plugs or disks may be placed in position. The closure V12 and cap 14 being removed, a needle attached to the detonating fuse may be inserted into the top or bottom of the gun and threaded through the passageways 38, the detonating fuse following therethrough.,`,.

The closure 12 may be replaced, the fuse connected with the detonating mechanism in the cap 14, and the cap 14 replaced. Thereafter, the gun may be lowered into the well and the perforating accomplished in the usual manner.` Upon use and reuse of the gun, it will be seen that the extremities of the housing 34 protect the bores of the gun ports 24 and 26 to a substantial extent from the deleterious eiect of direct exposure to the explosive blast of the charge assembly.

Figure 3 shows a modification of the invention in that the length of the housing 34 is less than the interior diameter of the gun body. Instead of seating in the gun ports therefore the housing is provided with disks 62 having upturned retaining anges, which disks are holed to receive the extremities 64 of retaining tubes 66. The retaining tubes 66 extend through the small bores 68 of the gun ports 70, which gun ports have large counterbores 72 to receive in close lit the sealing disks 74, such sealing disks being adapted to be hammered into the said counterbores against the shoulders 76 of the gun ports. O-rings or other sealing means may be provided between the disks and shoulders if found necessary.

It will be seen that in this modification of the invention, the shaped charge assembly may not be inserted through the gun ports. On the contrary, the charge assemblies must be inserted endwise into the gun and held in position by a suitable tool while the retaining tubes 66 are inserted into the gun ports into the engagement with the disks 62. Upon their positioning, however, the

detonating fuse may be threaded through the passages 38 as before. It will be noted that in this embodiment of the invention, the charge assembly may have more than two extremities. For example, a charge assembly may have three extremities adapted to be directed outwardly through three gun ports circumferentially spaced about the gun. v

The departure of the yadaptation or the invention shown in Figure 4 from the assembly shown in Figure 3 is only in the provision of the particular interiorly iianged sealing plugs 78. They include the retaining tubes 66 which are used to engage the disks 62 and thus secure the charge assembly 16 in proper-position. Such sealing plugs are fully described and claimed ina copending application Serial No. 207,924, led January 26, 1951, by Henry H. Mohaupt and Bruce Gilbert, entitled Jet Carrier Sealing Plug, now U.S. Patent No. 2,765,739, issued October 9, 1956.

While there has been described what is at present considerled a preferred embodiment of the present invention, it willvbe apparent to those skilled in the art that various modifications and changes may be made Without departing from the essence of the invention, and it is intended to cover herein all such modifications and changes as come within the true scope and spirit of the appended claims.

I claim:

1. A shaped charge gun assembly for perforating well pipe comprising `an elongated cylindrical gun body providing a coaxial cylindrical chamber therein, the side wall of said gun body providing therein longitudinally spaced groups of pairs of diametrically opposed cylindrical ports of the same diameter; plugs inserted in said ports; a plurality of shaped charge assemblies each positioned in said chamber at one of said port groups, each said shaped charge assembly comprising an open-ended cylindrical housing having an outside diameter smaller than the diameter of said ports and a length greater than the diameter of said chamber and less than the outside diameter of said gun body with its extremities extending into and seated in the ports of its associated port group, explosive within said housing, said explosive having a pair of lined cavities each facing outwardly of an end` of said housing and through one of said ports, and means providing a transverse passage through said housing medially thereof and communicating with said explosive, said shaped charge assemblies being positioned to dispose said transverse passages in alignment axially of said chamber;

and a detonation fuse threaded through said passages in4 detonating relation to the explosive in said shaped charge assemblies; whereby the extension into and seating of the extremities of each said housing in the ports of its associated port group interposes the extremities of said housing between said explosive and said ports toV protect said ports to a substantial extent from the deleterious elect of direct exposure to the explosive blast of the charge assembly.

2. A shaped charge assembly as deiined in claim 1 wherein said gun body has removable end closures, facilitating threading of said detonation fuse through said passages.

References Cited in the le of this patent UNITED STATES PATENTS 2,252,996 Tow Aug. 19, 1941 2,462,784 Smith Feb. 22, 1949 2,494,256 Muskat et al. Ian. 10, 1950 2,506,836 Kaltenberger May 9, 1950 2,655,619 Neal Oct. 13, 1953 FOREIGN PATENTS 1 610,106 Great Britain Oct. 12, 1948 986,573 France Mar. 28, 1951 989,329 France May 23, 1951 lis-1.a. 

